Extraction of 3D Printed Material for Magnetically Tuned Frequency Selective Surfaces

A 3D additive printing process has been employed recently for manufacturing a wide variety of RF components on planar and conformal structures. The designing and modeling steps require an accurate extraction at RF frequencies of the electromagnetic properties of the PLA material used for 3D printing. The broadband extraction technique is based on the best fitting of the simulated (HFSS) S-parameters to the measured (VNA) S-parameters for microstrip transmission lines of different lengths. The microstrip transmission lines are modeled and fabricated on a combination of known RT/Duriod and unknown PLA materials to extract the dielectric constant and loss tangent of the PLA material. These extracted parameters are to be employed in designing a Frequency Selective Surface. An annular ring planar structure is designed based on the desired passband and stopband frequencies.